The present invention pertains to DC to DC switching power converters on semiconductor die, and more particularly to on-die power conversion using multiphase power converters.
DC to DC switching power converters are commonly used to convert one available DC voltage to another DC voltage, often needed for a particular set of semiconductor dies. Such power converters may use one or more electrically controlled switches, such as N- or P-Channel MOSFETs. The gates of the MOSFETs are controlled by a controller circuit which is often integrated onto a single semiconductor die. As electronic devices become faster, smaller and more portable, the need for increased electrical efficiency in DC to DC converters is becoming more important. Relatively small increases in electrical efficiency of power converters may result in much greater overall efficiency improvements in electronic systems.
Furthermore, the operating voltage of high speed microprocessors is reduced, device dimensions shrink. This allows semiconductor die to operate at higher frequencies and the number of transistors integrated on a single semiconductor die to increase. Therefore, more power is consumed by semiconductor die consume from a power supply. The current supply paths carrying current to a semiconductor die through a circuit board must carry proportionally more current as the voltage level decreases. As a result, the parasitic elements of the current path to a semiconductor die become more pronounced. For example, narrower track widths along with increased current result in increased series resistance and inductance producing increased ripple, power loss and voltage drop. Furthermore, increased current may requires a greater number of package pins and circuit pads for a die and reduces interconnect reliability.
Thus there is a general need for an improved power converter and power conversion method. There is also a need for an on-die power converter and power conversion method that reduce input noise and output voltage ripple. There is also a need for an on-die power converter and power conversion method that reduces area on a semiconductor die without reducing power-converter performance. There is also a need for an on-die power converter and power conversion method that allows circuit-board voltage regulation modules to provide higher voltage reducing the parasitic effects. There is also a need for an on-die power converter and power conversion method that reduces the number of pins required by a semiconductor die. There is also a need for an on-die power converter and power conversion method that improves interconnect reliability. There is also a need for an on-die power converter which generates one or more on-die voltages different from a voltage supplied to the die from an off die source.